Director Debora A. Plunkett filed a Form 4 with the SEC on October 29, 2026, reporting the acquisition of 2,348 deferred stock units in Mercury Systems Inc at a price of $0 on October 28, 2026.

Key Highlights

  • Reporting person: Debora A. Plunkett, Director of Mercury Systems Inc (NASDAQ:MRCY)
  • Transaction date: October 28, 2026
  • Securities acquired: 2,348 deferred stock units (DSUs) of Common Stock, acquired at $0
  • Transaction code: A (acquisition)
  • Beneficial ownership following transaction: 19,181 shares of Common Stock held directly
  • Vesting condition: DSUs vest on the earlier of the first anniversary of the grant date or the next annual meeting of shareholders
  • Conversion condition: Vested DSUs do not convert into shares until Plunkett ceases to be a member of the Board of Directors

Plunkett DSU Grant Details and Beneficial Ownership at Mercury Systems

According to the filing, Debora A. Plunkett, a director of Mercury Systems Inc, acquired 2,348 deferred stock units (DSUs) of Common Stock on October 28, 2026, at a price of $0. The transaction was reported under transaction code "A," indicating an acquisition. Following this transaction, the filing discloses that Plunkett directly beneficially owns 19,181 shares of Common Stock.

The filing includes a footnote explaining the nature of the DSUs. According to the disclosure, the units "vest on the earlier of the first anniversary of the grant date and the next annual meeting of shareholders." Additionally, the filing states that "vested DSUs do not convert into shares of common stock until the date on which the reporting person ceases to be a member of our Board of Directors." No derivative securities transactions were reported in Table II of the filing.

The Form 4 was signed by Douglas Munro as attorney-in-fact on October 29, 2026, and was filed as a single reporting person disclosure. The issuer is identified in the filing as Mercury Systems Inc, with the ticker symbol MRCY listed on NASDAQ.

What Was Disclosed

Director Debora A. Plunkett reported the acquisition of 2,348 DSUs in Mercury Systems Inc on October 28, 2026, at $0, bringing her directly held beneficial ownership to 19,181 shares. The DSUs convert to common stock only upon her departure from the Board.